I dont have two yet, but plan on waiting until Colton is about 3 before trying for another.
With me and my brothers, I'm the oldest (19), and I have three brothers. Ryan (16 next month), Leevi (14), and Daylon (11). My mom said she wished there was a bit of a bigger gap between Ryan and Leevi because they always faught more than Me and Ryan, or Leevi and Daylon.
I think it's cause Ryan and Leevi were more into the same things because they are only like 22 months apart. Whereas, when Ryan was growing up I was into different things; and when Daylon was growing up Ryan/Leevi were into different things.